Abstract: A process for electrolytically coating a substrate at a preselected second voltage. The process comprises the steps of: (i) immersing the substrate in an aqueous electrolytic bath comprising at least one soluble salt, the substrate acting as a first electrode; (ii) contacting a second electrode with the aqueous electrolytic bath; (iii) passing a current through the aqueous electrolytic bath at a first voltage which is less than the second voltage, the current comprising alternating current superimposed over direct current; (iv) increasing the first voltage to a second voltage over a period of time while continuing to pass the current through the aqueous electrolytic bath; (v) keeping the second voltage substantially constant thereby allowing the current to decrease; and (vi) thereby forming an oxide coating on the substrate.